#include <iostream>
#include <stdio.h>
using namespace std;
typedef long long LL;
LL res[1007];
const LL MOD=1e9+7;
int main() {
    LL n;
    scanf("%lld", &n);
    res[1]=1;
    res[2]=2;
    for (int i=3; i<=n; ++i) {
        res[i]=(res[i-2]+res[i-1])%MOD;
    }
    printf("%lld\n", (res[n]+MOD)%MOD);
    return 0;
}
